Genetic flexibility in the convergent evolution of hermaphroditism in Caenorhabditis nematodes
Genetic flexibility in the convergent evolution of hermaphroditism in Caenorhabditis nematodes
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DOI：
10.1016/j.devcel.2006.02.002
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发表时间：
2006-04-01
影响因子：
11.8
通讯作者：
Haag, ES
中科院分区：
文献类型：
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作者：
Hill, RC;de Carvalho, CE;Haag, ES
C.和秀丽隐杆线虫C. briggsae通过获得有限的精子发生而从雌性祖先进化而来。启动C。秀丽线虫两性精子发生需要雌性促进基因TRA-2的生殖系翻译抑制，这允许三种雄性促进蕨类基因的去抑制。雌雄同体精子发生的停止需要fem-3翻译抑制。我们证明了C. briggsae的雌雄同体发育不需要fem-2或fem-3，XO Cb-fem-2/3动物转化为雌雄同体，而不是像C.优雅的。对Cb-tra-2抑制子的详尽筛选确定了另外75个fem样突变体，但所有突变体都是自育的雌雄同体而不是雌性。因此，控制雌雄同体精子发生的作用在C.布里格塞C. elegans和C.因此，briggsae通过在核心性别决定途径的不同点进行干预，实现了自我生育。这些发现与两性畸形的趋同进化是一致的，其特征是相当大的发育遗传灵活性。
The self-fertile hermaphrodites of C. elegans and C. briggsae evolved from female ancestors by acquiring limited spermatogenesis. Initiation of C. elegans hermaphrodite spermatogenesis requires germline translational repression of the female-promoting gene tra-2, which allows derepression of the three male-promoting fern genes. Cessation of hermaphrodite spermatogenesis requires fem-3 translational repression. We show that C. briggsae requires neither fem-2 nor fem-3 for hermaphrodite development, and that XO Cb-fem-2/3 animals are transformed into hermaphrodites, not females as in C. elegans. Exhaustive screens for Cb-tra-2 suppressors identified another 75 fem-like mutants, but all are self-fertile hermaphrodites rather than females. Control of hermaphrodite spermatogenesis therefore acts downstream of the fem genes in C. briggsae. The outwardly similar hermaphrodites of C. elegans and C. briggsae thus achieve self-fertility via intervention at different points in the core sex determination pathway. These findings are consistent with convergent evolution of hermaphroditism, which is marked by considerable developmental genetic flexibility.